Governors for fuel pumps

ABSTRACT

A governor for a fuel injection pump includes a plurality of weights which effect axial movement of a member which in turn is coupled to the fuel control rod of the pump. Movement of the member by the weights is opposed by a spring, the force exerted by which can be adjusted by means of a roller interposed between the spring and a ramp defined on an arm. The reaction applied to the arm is taken by a coiled compression spring which when the speed of the engine is above a predetermined value, and when the roller is set so that maximum fuel is supplied to the engine, compresses to reduce as the engine speed continues to increase, the amount of fuel supplied to the engine.

' United States Patent 1191 Potter July 22, 1975 [54] GOVERNORS FOR FUEL PUMPS 3,791,362 2/1974 Nakamura 123/140 [75] Inventor: g s g Pouer London Primary ExaminerManuel A. Antonakas g Assistant Examiner-James Winthrop Cranson [73] Assignee: C. A. V. Limited, Birmingham. Attorney, Agent, or FirmHo1man & Stern England 22 Filed: Dec. 28, 1973 [57] ABSTRACT A governor for a fuel injection pump includesya plural- [211 App! 429l70 ity of weights which effect axial movement of a member which in turn is coupled to the fuel control rod of [30] Foreign Application Priority Data the pump. Movement of the member by the weights is Dec. 29, 1972 United Kingdom 60140/72 P by a spring the force exerted by which can be adjusted by means of a roller interposed between 52 US. Cl 123/140 R the Spring and a temp defined em The reaetien 51 Int. Cl. F02d 1/12 applied to the is take" by a coiled compression [58] Field 01 Search 123/140 R Spring which when. the Speed Of the engine is above a predetermined value, and when the roller is set so that [56] References Cited maximum fuel is supplied to the engine, compresses to UNITED STATES PATENTS reduce as the engine speed continues to increase, the

amount of fuel supplied to the engine. 3,185,141 5/1965 Miracki l23/14OR 3,759,236 9/1973 Standt 123/140 6 Clams, 3 Drawmg Flgures 43 Zlx 44 i 42 2O -2 27 1 r t 25 .11 4 3 26/ d is 19 O H 9 3 4 r -|4- l7 3 15 3 35 PATENTEDJUL 22 ms SHEET Zlll FIG.

1 GOVERNORS FOR FUELYPUMPS This invention relates to a governor for a'fuel'injection pump of the kind intended to supply fuel to an internal combustion engine, the pump, having an adjustable control rod the setting of which determines the amount of fuel delivered by the pump, the governor comprising a housing, centrifugally operable means mounted within the housing and in use, driven at a speed representative of engine speed, a member'movable by said means, a lever pivotally mounted in the housing and adapted for connection at one end to said control rod, said lever at its other end bearing on said member, whereby as the speed of the engine increases the lever will move in a direction to effect a reduction in the quantity of fuel supplied to the engine, a-leaf spring acting on said member'in a direction to oppose the action of said means, a ramp located within the housing, roller means acting intermediate the ramp and the leaf spring and means for adjusting the setting of said roller whereby the force exerted by the leaf spring on said member can be adjusted.

The object of the invention is to provide such a governor in a simple and convenient form. V

According to the invention, in a governor of the kind specified the ramp is movably mounted within the housing, and there is interposed between the ramp and the housing, resilient means which as the speed of operation of the engine continues to increase above a predetermined value, will be compressed thereby causing movement of the lever in a direction to reduce the amount of fuel supplied by the pump.

One example of a governor in accordance with the invention will now be described with reference to the accompanying drawings in which: I

FIG. 1 is a sectional side elevation to the governor and showing it attached to a portion of a fuel injection FIG. 2 is a side elevation of a portion of the governor shown in FIG. 1, and FIG. 3.shows the characteristic of the governor of FIG. 1.

Referring to FIG. 1 of the drawings, there is provided a fuel pump which comprises a plurality of individual injection pumps arranged to supply fuel to respective injectors associated with the cylinders of the engine respectively. The pump includes a cam shaft 11 which extends from one end of the pump into a housing 12 of the governor. The cam shaft is driven by the associated engine in timed relationship therewith.

Mounted on the extended portion of the cam shaft 1 1 is a centrifugally operable means 13, which includes a plurality of pivotal weights 14 mounted upon a part which is secured to the cam shaft. The centrifugally operable means includes a sleeve 15 having a flange 16. Mounted about the sleeve 15 is a collar 17 and interposed between the collar and the flange 16 is a thrust bearing.

Pivotally mounted within the housing is a lever 18 which has a pivot axis indicated at 19. The lower end of the lever is bifurcated, the limbs having pins which engage within a groove formed in the periphery of the collar 17. The upper end of the lever 18 is forked and is engaged with the control rod of the pump. In operation, as the speed of rotation of the cam shaft increases, the weights 14 will move outwardly and the lever 18 will pivot about the pivot axis 19 and impart axial movement to the control rod 20 in a direction to reduce the amount of fuel supplied by the pump to the engine.

Also provided is a leaf spring 21, which as shown more clearly in FIG. 2 comprises two main leaves 22' having interposed therebetween afurther leaf 23 of thinner section. The upper end of the leaf spring 21 is pivotally mounted at one end about a pivot 24. At its P roller assembly 27 which includes a first roller engaging with'the ramp, and a second roller which engages with the leaf spring 21. The roller assembly is located within anarm 28,the armbeing mounted upon an angularly movable shaft 29' adjustable from the exteriorof the housing; Movement of the arm 29 which'in practice is connected to a manually operable control member,va-

ries the force which is exerted upon the leaf spring by the roller assembly, and as will be seen from FIG. 1, as

H the roller assembly 27' is moved downwardly, the spring is bowed and thereby exerts greater force on the collar 17. The force exerted by the leaf spring opposes the actionof the governor weights. At its lower end the arm 25 defines a housing for a plunger 35, which is loaded by a light coiled compression spring 36. Moreover, adjustably mounted within the housing is an adjusting member 37 which houses a further plunger 38 loaded by resilient means in the form of a coiled compression spring 39. Both plungers and 38 can partake of limited movement under the action of their respective springs. Additionally the arm 25 carries a pair of pins 40 which extend inwardly for possible engagement as will be described, With a flange 41 formed on the sleeve 15.

Mounted on thecontrol rod 20 is an abutment plate 42 which can engage with a pair of stops. The stop 43 determines the maximum fuel which can be supplied to the engine in normal circumstances, and the second stop 44 permits the control rod 20 to move an additional amount so that the pump will supply excess fuel for starting purposes.

If we refer to FIG. 3, the maximum fuel delivery line is indicated at 45 and it will be seen that it includes a substantially horizontal portion, this being determined by the stop 43. Also shown by dotted line 46 is the excess fuel delivery which is obtained when the stop 44 is brought into operation. The stops 43 and 44 are slidably mounted upon a rod operable from the exterior of the housing. When the stop 43 is removed from the abutment 42, and with the arm 28 set to the maximum fuel position, the spring 36 moves the plunger 35 and the arm 25 pivots about its axis 24, and at the same time imparts movement to the sleeve 17 through the intermediary of the roller assembly and the main leaf spring. The collar 17 is moved in a direction towards the pump and the control rod 20 moves an additional amount in order to obtain excess fuel. During this movement the pins 40 engage with the flange 41. As soon as the engine speed increases, the weights 14 will move outwardly and compress the spring 36 so that the various parts return to the position shown in FIG. 1'.

Starting from the position shown in FIG. 1, as the speed of operation of the engine increases, the force exerted by the governor weights will gradually increase and a point will be reached at which the spring force exerted by the spring 39 upon the lever 25 and therefore the collar 17 is overcome by the force exerted by the governor weights. When this occurs, pivotal movement of the lever 18 will occur and the control rod 20 will be moved to reduce the amount of fuel supplied to the engine. The shape of the portion 48 of the curve is determined by the spring 39, and it will be seen that before the force exerted by the spring 21 is overcome, and therefore before deflection of the spring 21 occurs, the spring 39 will start to be compressed. The speed at which this occurs depends upon the pre-load applied to the spring 39, and during compression of the spring 39 a progressive but gradual reduction in the fuel supplied to the engine occurs with increasing speed. The shape of the portion 47 of the fuel delivery curve is determined by the leaf spring 21, and it will be seen that as the speed of operation increases the fuel will gradually be reduced to zero. The above description of operation assumes that the arm 28 is set by the driver to give the maximum torque from the engine. In the event that the driver is not demanding the maximum torque and the speed is below the speed at which the spring 39 just starts to compress, then the reduction of fuel with increasing speed will be obtained solely as a result of the leaf spring 21. The shape of the resulting curve is shown at 50.

FIG. 3 shows an additional line 49 having a different slope to that of portion 47 of the maximum fuel characteristic. The line 49 is obtained as a result of the effect of the leaf spring 23, and it results when the arm 28 is set in the idling position as shown in FIG. 2, in increased sensitivity of the governor at idling speeds.

I claim:

1. In combination with an internal combustion engine, a governor, a fuel injection pump of the type intended to supply fuel to an internal combustion engine, the pump having an adjustable control rod the setting of which determines the amount of fuel delivered by the pump, the governor comprising a housing, centrifu gally operable means mounted within the housing and in use, driven at a speed representative of engine speed, a member movable by said means, a lever pivotally mounted in the housing and connected at one end to said control rod, said lever at its other end bearing on said member, whereby as the speed of the engine increases the lever will move in an direction to effect a reduction in the quantity of fuel supplied to the engine, a leaf spring acting on said member in a direction to oppose the action of said means, a ramp located within the housing, roller means acting intermediate the ramp and the leaf spring, means for adjusting the setting of said roller whereby the force exerted by the leaf spring on said member can be adjusted, said ramp being movably mounted within the housing and there being interposed between the ramp and the housing, resilient means which as the speed of operation of the engine continues to increase above a predetermined value, will be compressed thereby causing movement of the lever in a direction to reduce the amount of fuel supplied by the pump.

2. A governor as claimed in claim 1 in which said resilient means acts as a substantially rigid abutment below said predetermined speed.

3. A governor as claimed in claim 2 including additional resilient means acting between said first mentioned resilient means and said ramp.

4. A governor as claimed in claim 3 in which said resilient means and said additional resilient means comprise coiled compression springs, and means for limiting the extent of extension of the resilient means.

5. A governor as claimed in claim 4 including a pivotal arm, said additional resilient means being mounted on said pivotal arm, and said ramp being defined on said pivotal arm.

6. A governor as claimed in claim 5 in which said first mentioned resilient means is adjustably mounted on the housing. 

1. In combination with an internal combustion engine, a governor, a fuel injection pump of the type intended to supply fuel to an internal combustion engine, the pump having an adjustable control rod the setting of which determines the amount of fuel delivered by the pump, the governor comprising a housing, centrifugally operable means mounted within the housing and in use, driven at a speed representative of engine speed, a member movable by said means, a lever pivotally mounted in the housing and connected at one end to said control rod, said lever at its other end bearing on said member, whereby as the speed of the engine increases the lever will move in an direction to effect a reduction in the quantity of fuel supplied to the engine, a leaf spring acting on said member in a direction to oppose the action of said means, a ramp located within the housing, roller means acting intermediate the ramp and the leaf spring, means for adjusting the setting of said roller whereby the force exerted by the leaf spring on said member can be adjusted, said ramp being movably mounted within the housing and there being interposed between the ramp and the housing, resilient means which as the speed of operation of the engine continues to increase above a predetermined value, will be compressed thereby causing movement of the lever in a direction to reduce the amount of fuel supplied by the pump.
 2. A governor as claimed in claim 1 in which said resilient means acts as a substantially rigid abutment below said predetermined speed.
 3. A governor as claimed in claim 2 including additional resilient means acting between said first mentioned resilient means and said ramp.
 4. A governor as claimed in claim 3 in which said resilient means and said additional resilient means comprise coiled compression springs, and means for limiting the extent of extension of the resilient means.
 5. A governor as claimed in claim 4 including a pivotal arm, said additional resilient means being mounted on said pivotal arm, and said ramp being defined on said pivotal arm.
 6. A governor as claimed in claim 5 in which said first mentioned resilient means is adjustably mounted on the housing. 